(one's) line of country British phrase
A subject one is knowledgeable or likes a lot
Maths is my line of country. I could spend hours unraveling the mathematical puzzle.
Psychology is her line of country. She has treated a number of emotionally disturbed children.
Realizing that cooking is my line of country, I decided to pursue vocational education to be a skilled chef rather than attending university.
I have quitted my current job because it is not my line of country.
Have a strong feeling of affection for someone or something
To have experience and understand of how bad or unplesant something is
If you are in/get into somebody's good/bad books, you have/not have their favour.
To give someone or something better treatment than others.
Know a lot about something
The origin of this phrase is not clear.
Said when you are frightened to do something again because you had an unpleasant experience doing it the first time
After being cheated by her husband, Jane loses her belief on marriage and doesn't want to start any new relationship - a scalded dog fears cold water.